EMVE3601 Optimal operation of motors in buildings Course description

The students are expected to acquire knowledge about: Optimisation of the electricity grid, the working principle and structure of single-phase, three-phase, asynchronous and PM/EC motors, how to optimise the motor’s energy consumption by using override and subordinate control systems, e.g. power electronics, how motors respond to different loads such as pumps and fans in ventilation and pipe systems, and the use of soft starters and frequency converters.

The elective course is initiated only if a sufficient number of students choose the course.

The course builds on courses from the first and second years of study. Some knowledge of electro technique is expected.

No requirements over and above the admission requirements.

After completing the course, the student is expected to have achieved the following learning outcomes defined in terms of knowledge, skills and general competence:

Knowledge

The student

• is capable of explaining the difference between the concepts of control and regulation
• is capable of explaining the most important network quality parameters and requirements for delivery by network companies
• is familiar with the working principle and structure of a three-phase asynchronous motor
• is capable of explaining the motor’s torque and current consumption at start-up and during operation
• is capable of explaining the most common operational characteristics of the motor
• is capable of explaining the motor’s protection rating, the form of cooling, its mode of operation and insulation class
• is capable of explaining speed control using a static frequency converter
• is familiar with the effect of backflows in frequency converters in the form of harmonic distortion
• is capable of explaining the structure and working principle of soft starters
• is capable of explaining motor applications such as pumps and fans
• is capable of explaining the working principle of PM/EC motors
• is capable of interpreting the concept of SFP (specific fan power), especially in relation to electrical input
• is capable of explaining override control systems such as central processing systems, as well as subordinate control systems such as KNX networks and programmable logic controllers (PLC)
• is familiar with the principle of single-phase motors for operating small pumps and fans in ventilation and pipe systems

Skills

The student is capable of

• distributing electric noise such as flickering, asymmetry, voltage drops and harmonic distortion according to the load conditions in a building
• calculating current and torque during idling and operation for an asynchronous motor
• interpreting a motor’s torque curve and finding out when the motor is working optimally
• determining a motor’s protection rating and the form of cooling
• carrying out simple KNX programming
• interpreting a main current and control current circuit diagram in connection with direct start of a motor
• interpreting the control current circuit diagram of a ventilation system in a private home

General competence

The student is capable of

• communicating with other specialists in a technical environment about electric motors and their operation
• identifying electric motors in a ventilation and pipe system and is familiar with the control principles
• in an overall context, select the right pump and fan that meet the specified requirements and the requirement for optimum power consumption

Lectures, exercises, project work, laboratory work and an excursion to a supplier of frequency converters. It is recommended that students work 5-6 hours per week on their own.

The following required coursework must be approved before a student can take the exam:

• 1 assignment, 3 hours including preparation
• 1 lab exercise in groups.

1) Individual written exam, 3 hours, weighted 80%

2) Group project with presentation, weighted 20%

Part 1) of the exam: The exam results can be appealed.

Part 2) of the exam: The exam results cannot be appealed.

Both parts of the exam must be awarded grade E or better for the student to pass the course.

A resit or rescheduled exam may take the form of an oral exam. If oral exams are used for resit and rescheduled exams, the result cannot be appealed.

1. All printed and written aids, as well as a handheld calculator that cannot be used for wireless communication. If the calculator’s internal memory can store data, the memory must be deleted before the exam. Random checks may be carried out.
2. All.

Grade scale A-F.

1) One internal examinrs.

2) Two internal examiners.

External examiners are used regularly.